Autophagic vacuoles are a frequent feature in numerous neuromuscular disorders and myopathies. Among these, Dannon disease is the most known. However, there are other vacuolar myopathies or autophagic vacuolar myopathies, including, for example, X-linked myopathy with excessive autophagy (XMEA), infantile autophagic vacuolar myopathy, adult-onset autophagic vacuolar myopathy with multi-organ involvement, and X-linked congenital autophagic vacuolar myopathy. See, e.g., Nishino, I., “Autophagic vacuolar myopathy,” Semin Pediatr Neurol 13:90-95 (2006), the entire contents and disclosure of which is hereby incorporated by reference. Currently, patients suffering from muscular dystrophy, including limb-girdle muscular dystrophy, are often tested by taking an invasive muscular biopsy from affected patients followed by pathological study to diagnose or rule out particular types of disease. Furthermore, existing methods may leave an exact diagnosis uncertain due to similar characteristics and symptoms displayed by various vacuolar myopathies. A need exists in the art for improved compositions and methods for diagnosing and distinguishing among various types of limb-girdle muscular dystrophy and/or vacuolar or vacuolated myopathies that do not require such invasive procedures and that are capable of giving more accurate and definite results.